Tube-pushing bench



Oct. 19, 1937. H. HEETKA-MP TUBE PUsxuNG' BENCH Filed urch `5, 195eFIS-4 Patented Oct. 19, 1937 PATENToFFIcE TUBE-PUSHING BENCH HeinrichHeetkamp, Dusseldorf, Germany, as-

signor to Demag Aktiengesellschaft, Duisburg,

Germany Application March 5,

1936,`seria1 N6. 67,309

In Germany March 7, 1935 4 Claims..

In order to ensure the smooth working of tube draw benches operating ata high speed, it is advisable to provide guides not only in front of thebed of rings or reducing dies but also inthe bed 5 between the rings orreducing dies. Hitherto for this purpose guide rings inserted betweenthe reducing dies have been employed, but according to recent proposalsguides have been provided in which the guiding elements are disposedradially in such manner as to be adjustable relatively to each other andare resilient, while at the same time they are forced into ltheoperative position by means of a suitable pressure medium. Guide ringshave the disadvantage that only the mandrel with the bloom and not thepush rods which require to be prevented from bending are directlyenclosed and supported, so that thus undesirable bending of the mandrelpush-rods is possible. The guiding devices of the kind hereinbeforedescribed avoid these disadvantages, but on the other hand they have thedisadvantage of being complicated in construction, and giving trouble byreason of the resilience provided, having regard to the fact that theforces occurring are uncontrollable in their intensity.

To avoid these disadvantages, according to the invention the rigidclosed guides herelnbefore referred to are employed, and thedisadvantage of the open guide is avoided by the fact that the guidescan be skewed for the purpose of changing the effective cross-sectionalshape of the passage through them. The rocking axis of the guides willadvantageously intersect the drawing axis, although as will be obviousthe non-coincidence of the skewing axis with the drawing axis isunimportant. It is advisablel to form the hole in the closed guideswhich forms the mandrel guide, as a regular polygon, but moreparticularly a hexagon, so that the mandrel or push-rod is effectivelysupported at diametrically opposite positions.

The invention is diagrammatically illustrated in the accompanyingdrawing, by way of example.

Figures l to 3 illustrate the construction of apparatus according to theinvention in longitudinal section, in front elevation and in sideelevation respectively.

Figure 4 shows the method by which the guide member according to'theinvention is fitted in the draw bed.

' Figures 5 and 6 illustrate a possible construction of the device foradjusting the guide and Figure '7 shows diagrammatically a dispositionof the skewing axis for the guide member other than that illustrated inFigures 1 to 6.

Referring to the drawing, I denotes the closed guide member. The hole ineach guide member I which forms the actual guide is hexagonal in shape,as shown in Figures 2 and 3, and thus the mandrel push-rodl iscontrolled at four diametrically opposite points when the guide isskewed, while when the guide is disposed normally the work upon themandrel may be supported at six points. As Figure 4 shows, the members Iare tted to the draw bed'Z in such manner that they can be rotatedaround their respective axes A-A. In Figure l the guide member I isdisposed at right angles to the mandrel 3 and to the tubular body 4surrounding the mandrel (cf. the guide member in the uppermost positionof Figure 4). In this position of the guide members I the latter providefree passage for the mandrel and the blank. In order that the mandrelfreed of the blank or the push-rod 'may be rmly guided in the draw bed,the guide members I are skewed by partial rotation around thecorresponding axis A-A. As will be seen by reference to Figures 2 and 3,oppositely disposed edges of the hexagonal hole in the guide member Irespectively at the front and ear faces bear against the mandrel orpush-rod at 5, so that the latter cannot be deected from its axialposition or be bent. In Figure 4 three guide members I are shown skewedinto the guiding position.

For the purpose of skwing the guide members a wedge in conjunction witha spring can be employed, as shown by Way of example in Figures 5 and 6.According to these constructions the guide member I is mounted in theframe 6 so4 as to be capable of skewing around the axis A-A, the stop1-which may be a screw-limiting Athe amount of deection. The frame 6 isinset into the draw bed. The spring 8 tends to maintain the guide memberI in the position of rest shown in Figure 1 and in the uppermostposition of Figure 4. The guide member I is adapted to be forced intothe skewed position by the use of a wedge 9 acting in conjunction with aprojection I 0 o n the guide member I. The wedge 9 is advanced bymechanism for the purpose provided inthe casing I, I; this causes theguide member I to skew as shown in Figures 2 and 3.

Figure 7 illustrates a possible alternative arrangement in which ltheskewing axis for the guide member I is disposed away from the axis ofthe mandrel.

The invention is not limited to a particular form of the hole in theguide member I which constitutes the guide member. It is advantageoushowever to form the hole as a regular polygon as shown in the drawing.

I claim:

1. Tube vdraw benches provided with closed rigid guide members disposedin iixed position in the draw bed, and whose guide passages are largerthan the diameter of the mandrel and which guide members by skewingduring the forward thrusting movement of the mandrel apply theiroppositely disposed edges against the mandrel to form fixed guidingpassageways therefor.

2., In tube draw benches, a rigid closed guide member for the mandreland mandrel push-rod and means for skewing the guide member in relationto the drawing' axis of the bench, the said the provision of apassageway in the guide member of the form of a hexagon.

rmmRIcH

